Nitrogen Metabolism and Nitrogen Requirements of the Brushtail Possum, Trichosurus Vulpecula (Kerr).

Abstract

Nitrogen metabolism was studied in adult Trichosurus vulpecula maintained on semipurified diets of different nitrogen and fibre contents. The maintenance nitrogen requirement was estimated to be 203 mg per kg W*0.75 per day on a dietary basis, and a mean of 189 mg per kg W*0.75 per day on a truly digestible basis. Both are low compared with estimates from most eutherians, and are similar to estimates from macropods adapted to arid zones. Metabolic faecal nitrogen (mg per 100 g dry matter intake) was directly related to dietary fibre level, viz. 336 on 41% neutral detergent fibre (NDF) diets, 184 on 17% NDF diets, and 78 on 9.5% NDF diets. Dry matter intakes were low compared with those of the rabbit, suggesting that, as with nitrogen, the maintenance energy requirement of the brushtail is below that of most eutherians.